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Being fluorine-free and a high performance material as a small organic acceptor molecule, BTP-eC9 has been well mixed with BDT-based PM6 donor polymers for providing satisfactory photovoltaic properties, especially towards future large scale/large area solar cell production. However, as one of the key electrical outputs from such binary active layer materials, the open circuit voltage (VOC) was limited to ca. 0.84 V, which needs to be further improved for BTP-eC9 to have a bright future. This paper focuses on the molecular design of alkylthio- and alkoxy-phenyl flanked benzo[1,2-b:4,5-b′]dithiophene-based conjugated polymers (PBDT-PS-ttTPD or P10 for short and PBDT-PO-ttTPD or P11), which were successfully synthesized and applied as donor materials for pairing with BTP-eC9 in organic photovoltaic (OPV) devices. By fine-tuning the side chains of the benzodithiophene (BDT) moiety, such non-fullerene OPV devices with normal configuration demonstrate an attractively high open circuit voltage (VOC) of 0.89 and 0.87 V in P10/BTP-eC9 and P11/BTP-eC9 based binary single bulk heterojunction OPV devices, while still maintaining an excellent JSC of 22.7 and 20.0 mA cm−2 with a final power conversion efficiency (PCE) of 12.93% and 9.37%, respectively. The alkylthio-phenyl chain substituted BDT polymer exhibits better photovoltaic performance in all aspects than the alternative with alkoxy chains due to the synergistic effect of the alkylthio-phenyl flanked BDT, TPD, and π-bridge (thieno[3,2-b]thiophene).

An asymmetric wide-bandgap acceptor, namely AITC, is synthesized. The large dipole moment of AITC reinforces the molecular packing in ternary blends. Single-junction and tandem OSCs yielded a remarkable PCE of 18.8% and 19.4%, respectively.

The Heisenberg antiferromagnetic spin-1/2 chain, originally introduced almost a century ago, is one of the best studied models in quantum mechanics due to its exact solution, but nevertheless it continues to present new discoveries. Its low-energy physics is described by the Tomonaga-Luttinger liquid of spinless fermions, similar to the conduction electrons in one-dimensional metals. In this work we investigate the Heisenberg spin-chain compound YbAlO3 and show that the weak interchain coupling causes Umklapp scattering between the left- and right-moving fermions and stabilizes an incommensurate spin-density wave order at q = 2kF under finite magnetic fields. These Umklapp processes open a route to multiple coherent scattering of fermions, which results in the formation of satellites at integer multiples of the incommensurate fundamental wavevector Q = nq. Our work provides surprising and profound insight into bandstructure control for emergent fermions in quantum materials, and shows how neutron diffraction can be applied to investigate the phenomenon of coherent multiple scattering in metals through the proxy of quantum magnetic systems., A field-induced incommensurate spin density wave order was observed in the spin-chain material YbAlO3; however, its mechanism is not fully understood. Here, using neutron scattering and numerical calculations, the authors propose a mechanism based on multiple fermion scattering caused by weak inter-chain coupling.

Background : Aberrant DNA methylation patterns are of increasing interest in the study of psoriasis mechanisms. This study aims to screen potential diagnostic indicators affected by DNA methylation for psoriasis based on bioinformatics using multiple machine learning algorithms and to preliminarily explore its molecular mechanisms. Methods : GSE13355, GSE14905, and GSE73894 were collected from the gene expression omnibus (GEO) database. Differentially expressed genes (DEGs) and differentially methylated region (DMR)-genes between psoriasis and control samples were combined to obtain differentially expressed methylated genes. Subsequently, protein-protein interaction (PPI) network establishment, multiple machine learning algorithm analysis, including, the least absolute shrinkage and selection operator (LASSO), Random Forest (RF), and Support Vector Machine (SVM), receiver operating characteristic (ROC) curve analysis, and single-gene gene set enrichment analysis (GSEA) were performed to analyze the interaction networks, to recognize hub genes, and to clarify the pathogenesis of psoriasis. The druggable genes were predicted using DGIdb. The expression of GJB2 in psoriasis lesions and healthy controls was detected by immunohistochemistry (IHC) and quantitative real-time PCR(RT-qPCR). Results: In this study, a total of 767 DEGs and 896 DMR-genes were obtained. Functional enrichment showed that they were significantly associated with skin development, skin barrier function, immune/inflammatory response, and cell cycle. The combined transcriptomic and DNA methylation data resulted in 33 differentially expressed methylated genes, of which The gap junction beta 2 (GJB2) was the final identified hub gene for psoriasis, with the robust diagnostic power. IHC and RT-qPCR showed that GJB2 was significant higher in psoriasis than that in healthy controls. Single gene GSEA suggested that GJB2 may be involved in the development and progression of psoriasis by disrupting the body's immune system, mediating the cell cycle, and destroying the skin barrier, in addition to possibly inducing diseases related to the skeletal aspects of psoriasis. Moreover, OCTANOL and CARBENOXOLONE were identified as promising compounds through the DGIdb database. Conclusion: Our findings suggest that the abnormal expression of GJB2 may play a critical role in psoriasis development and progression. The genes identified in our study may serve as a diagnostic indicator and therapeutic target in psoriasis.

We designed and synthesized a series of fused-ring electron acceptors (FREAs) based on naphthalene-fused octacyclic cores end-capped by 3-(1,1-dicyanomethylene)-5,6-difluoro-1- indanone (NOICs) using a bottom-up approach. The NOIC series shares the same end groups and side chains, as well as similar fused-ring cores. The butterfly effects, arising from different methoxy positions in the starting materials, impact the design of the final FREAs, as well as their molecular packing, optical and electronic properties, charge transport, film morphology, and performance of organic solar cells. The binary-blend devices based on this NOIC series show power conversion efficiencies varying from 7.15% to 14.1%, due to the different intrinsic properties of the NOIC series, morphologies of blend films, and voltage losses of devices.

Traditional pharmacotherapy suffers from multiple drawbacks that hamper patient treatment, such as the buildup of antibiotic resistances or low drug selectivity and toxicity during systemic application. To overcome these challenges, drug activity can be controlled by employing delivery, targeting, or release solutions that mostly rely on the response to external physicochemical stimuli. Due to various technical limitations, mechanical force as a stimulus in the context of polymer mechanochemistry has so far not been used for this purpose, yet it has been proven to be a convenient and robust method to site-selectively rearrange or cleave bonds with submolecular precision in the realm of materials chemistry. Here, we present an unprecedented mechanochemically responsive system capable of successively releasing small furan-containing molecules, including the furylated fluorophore dansyl and the drugs furosemide as well as furylated doxorubicin, by ultrasound-induced selective scission of disulfide-centered polymers in solution. We show that mechanochemically generated thiol-terminated polymers undergo a Michael-type addition to Diels-Alder (DA) adducts of furylated drugs and acetylenedicarboxylate derivatives, initiating the downstream release of the small molecule drug by a retro DA reaction. We believe that this method can serve as a blueprint for the activation of many other small molecules.

To develop high-efficiency polymer solar cells (PSCs), the acceptors in a bulk heterojunction (BHJ) blend are supposed to possess complementary absorption bands in the near-infrared region and a suitable energy level to be well-matched with the donors. In this work, a new small molecular acceptor (SMA) named IDTT8-N based on an indacenodithienothiophene (IDTT) core was designed and synthesized. In comparison to the counterpart molecule IDTN with an indacenodithiophene (IDT) core, IDTT8-N with the extended π-conjugation length of an IDT core not only exhibits a red shift of ca. 35 nm in optical absorption but also has little change on its lowest unoccupied molecular orbital (LUMO) energy level. Therefore, PSCs based on PM6:IDTT8-N exhibit a superior short-circuit current density (Jsc) and high open-circuit voltage (Voc). Moreover, apart from the strong face-on molecular stacking, distinct end-group π-πstacking of IDTT8-N can be observed in the blends, facilitating the charge transport. Therefore, the optimized PM6:IDTT8-N-based devices exhibit dramatically high and balanced electron mobility (μe) and hole mobility (μh), whose magnitudes are over 10-3 cm2 V-1 s-1. Consequently, an extraordinary PCE of 14.1% with a relatively high Jsc of 20.98 mA cm-2 and a Voc of 0.94 V was recorded. To our knowledge, it is the new record among PSCs with a SMA based on 2-(3-oxocyclopentylidene)malononitrile (INCN) as end groups. These results indicate that extending the π-conjugation length of the fused ring core of a SMA is an efficient method to both enhance the absorption and the molecular interaction of the acceptor as well as the photovoltaic performance of PSCs.

The effects of guar gum (GG), xanthan gum (XG), carrageenan gum (CG), xanthan-guar gum blend (XG-GG), chitosan (CS), gum arabic (GA) on the water migration, rheological and 3D printing properties of β-carotene loaded yam starch-based hydrogel (BCH) were investigated to expand product form of β-carotene. The results showed that CS addition promoted the migration of weakly bound water to tightly bound water in BCH. Addition of GG, CG, XG-GG, CS and GA enhanced apparent viscosity, G', G'', hardness and gumminess of BCH. CG, XG-GG, CS and GA addition improved printing stability of BCH. The printed objects added with GG and CS displayed smooth lines with fine resolution and higher formability, which showed a more uniform pore distribution and thinner gel skeleton structure. The results of XRD showed that hydrocolloids addition decreased the relative crystallinity of BCH. A combination of physicochemical parameters could be used to discriminate samples through hierarchical cluster analysis.

It had been commonly accepted in the organic photovoltaic (OPV) community that subtle variations in the molecular structure of active layer materials would cause profound impacts on their aggregating structure and blend morphology and therefore the performance of such polymer solar cells (PSCs). Herein, we employed an electron-deficient building block 3,6-dithiophenyl-2-carboxylate pyrazine (DTCPz) for constructing one series of promising donor terpolymers of PMZ1, PMZ2, and PMZ3, respectively, gaining their relatively lower-lying highest occupied molecular orbital (HOMO) energy levels, more closed π-π stacking and enhanced crystallinity in thin films, and lower miscibility with acceptor Y6, in comparison with their parent polymer counterpart (namely PM6). Reaching DTCPz moieties up to 20% (mol/mol%) in its terpolymer composition, the resulting polymer (PMZ2) achieved more favorable phase separation with improved exciton dissociation, and charge transport and extraction. As a result, an outstanding fill factor of 77.2% and a promising power conversion efficiency of 17.8 % was achieved. Moreover, the corresponding device shows better thermal stability over the PM6-based one. This work suggests a facile method for significantly improving the thin film morphology of the active-layer materials via fine-tuning the chemical structure of electron-deficient units on the backbone of the wide bandgap donor polymer, therefore achieving enhanced photovoltaic performance and thermal stability for practical applications.

ObjectiveHearing loss is the most common initial symptom in patients with sporadic vestibular schwannomas (SVS). Hearing preservation is an important goal of both conservative and surgical therapy. However, the mechanism of SVS-associated hearing loss remains unclear. Thus, we performed this systematic review to summarize the current understanding of hearing loss in the SVS and distill a testable hypothesis to further illuminate its underlying mechanism.MethodsA systematic review querying four databases (PubMed, Medline, Embase, and Web of Science) was performed to identify studies evaluating hearing loss in patients with SVS and exploring the potential mechanisms of hearing impairment.ResultsA total of 50 articles were eligible and included in this review. After analysis, the retrieved studies could be categorized into four types: (1) 29 studies explore the relationship between hearing loss and the growth pattern of the tumor (e.g., tumor size/volume, growth rate, tumor location, etc.); (2) ten studies investigate the potential role of cochlear dysfunction in hearing deterioration, including structural abnormality, protein elevation in perilymph, and cochlear malfunctioning; (3) two studies looked into SVS-induced impairment of auditory pathway and cortex; (4) in the rest nine studies, researchers explored the molecular mechanism underlying hearing loss in SVS, which involves molecular and genetic alterations, inflammatory response, growth factors, and other tumor-associated secretions.ConclusionsMultiple factors may contribute to the hearing impairment in SVS, including the growth pattern of tumor, cochlear dysfunction, impairment of auditory pathway and cortex, genetic and molecular changes. However, our current understanding is still limited, and future studies are needed to explore this multifactorial hypothesis and dig deeper into its underlying mechanism.

The Heisenberg antiferromagnetic spin-1/2 chain, originally introduced almost a century ago, is one of the best studied models in quantum mechanics due to its exact solution, but nevertheless it continues to present new discoveries. Its low-energy physics is described by the Tomonaga-Luttinger liquid of spinless fermions, similar to the conduction electrons in one-dimensional metals. In this work we investigate the Heisenberg spin-chain compound YbAlO

Herein, we fabricated all-polymer solar cells (all-PSCs) based on a fluorinated wide-bandgap p-type conjugated polymer PM6 as the donor, and a narrow bandgap n-type conjugated polymer PZ1 as the acceptor. In addition to the complementary absorption and matching energy levels, the optimized blend films possess high cystallinity, predominantly face-on stacking, and a suitable phase separated morphology. With this active layer, the devices exhibited a high V oc of 0.96 V, a superior J sc of 17.1 mA cm -2 , a fine fill factor (FF) of 68.2%, and thus an excellent power conversion efficiency (PCE) of 11.2%, which is the highest value reported to date for single-junction all-PSCs. Furthermore, the devices showed good storage stability. After 80 d of storage in the N 2 -filled glovebox, the PCE still remained over 90% of the original value. Large-area devices (1.1 cm 2 ) also demonstrated an outstanding performance with a PCE of 9.2%, among the highest values for the reported large-area all-PSCs. These results indicate that the PM6:PZ1 blend is a promising candidate for scale-up production of large area high-performance all-PSCs.

In this work, a novel narrow-bandgap conjugated polymer acceptor (PN1) based on electron-withdrawing 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis[3-((2-hexyldecyl)oxy)benzene]-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]dithiophene as the core building block and thiophene as the linking unit was developed and applied in all-polymer solar cells (all-PSCs). The PN1 exhibits a broad and strong absorption in the region of 550–800 nm with a high maximum extinction coefficient of 1.28 × 105 cm−1, a high electron mobility of 9.39 × 10−4 cm2 V−1 s−1 and more ordered molecular packing. In addition, it also possesses a relatively higher lowest unoccupied molecular orbital (LUMO) of −3.85 eV, which is beneficial to improve open circuit voltage (Voc) and reduce the energy loss of the device. By matching with the wide bandgap polymer donor PM6, the all-PSCs achieved a power conversion efficiency (PCE) of 10.5% with a large Voc of 1.0 V, a high short circuit current density (Jsc) of 15.2 mA cm−2 and a superior fill factor (FF) of 0.69. Our work demonstrated that PN1 is a promising polymer acceptor for application in all-PSCs.

Solution-processed perovskite films inevitably have a number of ionic defects, regarded as non-radiative recombination centers, which limit the overall efficiency and the stability of perovskite solar cells (Pero-SCs). Passivation of these defects has been proven to be an efficient strategy to suppress the charge recombination and thus improve the performance of Pero-SCs. Herein, for the first time, a π-conjugated and alcohol-soluble small molecule with bilateral carboxyl and thiophene groups, namely 2,5-di(thiophen-2-yl)terephthalic acid (DTA), was introduced into the MAPbI3-xClx (MA = CH3NH3) film to passivate the defects and enhance the performance of the corresponding planar p-i-n Pero-SCs. With high electron density, the symmetric carboxyl groups on both sides of DTA can effectively coordinate with unsaturated Pb2+ cations to passivate the defects in the perovskite. This efficient defect passivation can reduce the charge trap density and increase the carrier lifetime, which leads to a significant enhancement of the open-circuit voltage from 1.07 V for the control Pero-SC to 1.17 V for the passivated one, resulting in a power conversion efficiency (PCE) of 21.45%. The highest achieved Voc reaches 1.19 V, with a PCE of 21.40%, and the corresponding loss of Voc is only 0.38 V. In addition, the DTA passivated devices exhibit a photovoltaic performance with high reproducibility, as well as a significant improvement in environmental stability and thermal stability. This work demonstrates the great potential of DTA as an effective and promising additive to passivate the perovskite defects for the high performance of Pero-SCs.

Fluorine and alkylsilyl substitutions are two important strategies to reduce the energy levels and increase the absorption coefficient and hole mobility of photovoltaic materials simultaneously. Similar to fluorination, chlorination can also induce the intermolecular non-covalent interactions of Cl-H/S/Cl. Moreover, because chlorine (Cl) atoms contain empty 3d orbitals that can hold π-electrons from the conjugated skeleton, chlorination can decrease the molecular HOMO level more effectively than fluorination. Herein, we developed two wide bandgap polymer donors PBZ-Cl and PBZ-ClSi based on the Cl atom, and combined the Cl atom and alkylsilyl substituted thienyl benzodithiophene (BDTT-Cl and BDTT-ClSi) as donor units, respectively. From the control polymer PBZ to PBZ-Cl and then to PBZ-ClSi, the polymers show a gradually reduced HOMO level, increased absorption coefficient and improved charge mobility. As a result, the PBZ-ClSi:IT-4F-based PSCs fabricated by the nonhalogen solvents achieved a high power conversion efficiency (PCE) of 12.8% with a high open-circuit voltage (V oc ) of 0.93 V, short-circuit current density (J sc ) of 19.2 mA cm -2 , fill factor (FF) of 71.5% and a low energy loss of 0.57 eV, while the PSCs based on PBZ and PBZ-Cl only obtained lower PCEs of 6.4% and 9.7%, respectively. The PCE of 12.8% is one of the highest values recorded for nonhalogen solvent-processed PSCs to date. The results indicate that the combination of Cl atoms and alkylsilyl substituents is a simple and effective method for designing high efficiency polymer photovoltaic materials.

Developing organic solar cells based on a ternary active layer is one of the most effective approaches to improve their photovoltaic performance. However, limited success has been achieved in all-polymer solar cells (all-PSCs). In this study, a ternary all-PSC with improved efficiency and stability is realized by using J71 as the third component to adjust the host system of PBDB-T:PG1. The deeper highest occupied molecular orbital (HOMO) energy level of J71 downshifts the mixed HOMO energy levels of donors. The two polymer donors (PDs) have good miscibility and present Förster resonance energy transfer. When blended with PG1, the optimized morphology is obtained, showing enhanced crystallinity but meanwhile slightly reduced phase separation with improved exciton dissociation and collection efficiency, suppressed charge recombination, and reduced energy loss (0.55 eV). Combining the benefits mentioned above, the ternary all-PSC exhibits an excellent efficiency of 12.8% with simultaneously elevated open-circuit voltage (0.96 V), short-circuit current density (18.4 mA cm−2), and fill factor (72.2%). Moreover, the optimized ternary all-PSC shows improved storage and thermal stability. This study demonstrates that the utilization of a ternary all-polymer system based on two well-miscible PDs is an effective strategy to enhance the photovoltaic performance and stability of all-PSCs.

This paper is an interdisciplinary narrative review of efficacious non-invasive therapies that are increasingly used to restore function in people with chronic spinal cord injuries (SCI). First presented are the secondary injury cascade set in motion by the primary lesion and highlights in therapeutic development for mitigating the acute pathophysiologic process. Then summarized are current pharmacological strategies for modulation of noradrenergic, serotonergic, and dopaminergic neurotransmission to enhance recovery in bench and clinical studies of subacute and chronic SCI. Last examined is how neuromechanical devices (i.e., electrical stimulation, robotic assistance, brain-computer interface, and augmented sensory feedback) could be comprehensively engineered to engage efferent and afferent motosensory pathways to induce neuroplasticity-based neural pattern generation. Emerging evidence shows that computational models of the human neuromusculoskeletal system (i.e., human digital twins) can serve as functionalized anchors to integrate different neuromechanical and pharmacological interventions into a single multimodal prothesis. The system, if appropriately built, may cybernetically optimize treatment outcomes via coordination of heterogeneous biosensory, system output, and control signals. Overall, these rehabilitation protocols involved neuromodulation to evoke beneficial adaptive changes within spared supraspinal, intracord, and peripheral neuromuscular circuits to elicit neurological improvement. Therefore, qualitatively advancing the theoretical understanding of spinal cord neurobiology and neuromechanics is pivotal to designing new ways to reinstate locomotion after SCI. Future research efforts should concentrate on personalizing combination therapies consisting of pharmacological adjuncts, targeted neurobiological and neuromuscular repairs, and brain-computer interfaces, which follow multimodal neuromechanical principles.

Developing a high-performance donor polymer is critical for achieving efficient non-fullerene organic solar cells (OSCs). Currently, most high-efficiency OSCs are based on a donor polymer named PM6, unfortunately, whose performance is highly sensitive to its molecular weight and thus has significant batch-to-batch variations. Here we report a donor polymer (named PM1) based on a random ternary polymerization strategy that enables highly efficient non-fullerene OSCs with efficiencies reaching 17.6%. Importantly, the PM1 polymer exhibits excellent batch-to-batch reproducibility. By including 20% of a weak electron-withdrawing thiophene-thiazolothiazole (TTz) into the PM6 polymer backbone, the resulting polymer (PM1) can maintain the positive effects (such as downshifted energy level and reduced miscibility) while minimize the negative ones (including reduced temperature-dependent aggregation property). With higher performance and greater synthesis reproducibility, the PM1 polymer has the promise to become the work-horse material for the non-fullerene OSC community., The batch reproducibility of polymer donor materials limits the performance of polymer solar cells. Here Wu et al. develop a polymer donor PM1 by random terpolymerization strategy with a high efficiency of 17.6% in the device and excellent batch-to-batch reproducibility.

Regulating molecular structure to optimize the active layer morphology is of considerable significance for improving the power conversion efficiencies (PCEs) in organic solar cells (OSCs). Herein, we demonstrated a simple ternary copolymerization approach to develop a terpolymer donor PM6-Tz20 by incorporating the 5,5'-dithienyl-2,2'-bithiazole (DTBTz, 20 mol%) unit into the backbone of PM6 (PM6-Tz00). This method can effectively tailor the molecular orientation and aggregation of the polymer, and then optimize the active layer morphology and the corresponding physical processes of devices, ultimately boosting FF and then PCE. Hence, the PM6-Tz20: Y6-based OSCs achieved a PCE of up to 17.1% with a significantly enhanced FF of 0.77. Using Ag (220 nm) instead of Al (100 nm) as cathode, the champion PCE was further improved to 17.6%. This work provides a simple and effective molecular design strategy to optimize the active layer morphology of OSCs for improving photovoltaic performance.

Small molecular acceptors (SMAs) BTC-2F and BTH-2F, based on heptacyclic benzodi(cyclopentadithiophene) electron-donating core (CBT) with chlorinated-thienyl conjugated and thienyl conjugated side chains, respectively, are designed and synthesized. Compared with non-chlorine acceptor BTH-2F, BTC-2F exhibits slightly blue-shifted absorption spectra, similar the lowest unoccupied molecular orbital (LUMO) (–3.91 eV), deeper highest occupied molecular orbital (HOMO) energy level and higher electron mobility than that of BTH-2F. PM6, a wide bandgap polymer, is selected as the donor material to construct bulk heterojunction polymer solar cells processed with nonhalogenated solvent toluene. The optimized PM6:BTC-2F-based device presents a 12.9% power conversion efficiency (PCE), while the PCE of PM6:BTH-2F-based device is only 11.3%. The results suggest that it is an effective strategy to optimize the photoelectric properties of SMAs by incorporating chlorine atom into the conjugated side chains.

Hypothesis: Light-responsive microgels are interesting colloidal systems with potential applications in the biotechnology and medicine. However, synthesis of light-responsive microgels with high loading of photoswitchable molecules is still very challenging.Experiments: Herein we developed a new method to synthesize light and temperature dual-responsive spiropyran-modified poly(N-vinylcaprolactam) microgels. The novel and straightforward microgels syn-thesis route involved: a) synthesis of poly(N-vinylcaprolactam-co-vinylformamide) copolymers via RAFT polymerization followed by the hydrolysis to obtain primary amine groups, b) attachment of carboxyl modified spiropyran molecules to polymer chains via coupling, and c) crosslinking of spiropyranmodified polymer chains in W/O miniemulsion to form microgels.Findings: Via this method, we successfully synthesized poly(N-vinylcaprolactam) microgels containing more than 10 mol% spiropyran. The reversible light responsiveness of the spiropyran-modified copolymers and microgels in aqueous solution, which originates from the spiropyran photoisomerization under irradiation with different wavelengths, was demonstrated by UV-Vis spectroscopy. Spiropyran-modified copolymers demonstrate shift of the lower critical solution temperature (LCST) due to the polarity change of spiropyran molecules under dark, UV and visible light. Surprisingly, dynamic light scattering (DLS) results show that the microgels based on the same copolymers are less affected by UV irradiation. Microgels are swollen in darkness when spiropyran molecules are in the polar, merocyanine form, and collapse after irradiation with visible light, due to the transformation of spiropyran to the relatively nonpolar, closed spirocyclic form. In addition, the spiropyran-modified microgels exhibit reversible tem-perature responsiveness by presenting a volume phase transition in water from a swollen state to a collapsed state with increasing temperature and the transition temperature decreased compared to the pristine microgels due to the hydrophobicity of spiropyran units. (c) 2020 Elsevier Inc. All rights reserved.

In the past few years, fluorine atom has been widely introduced into organic semiconductor (OS) materials to improve the photovoltaic performance of polymer solar cells (PSCs). In contrast, chlorine atom is rarely concerned, although it is also a halogen element and is more easily introduced into OS materials. Herein, we designed and synthesized a new D-A-type two-dimension (2D)-conjugated polymer, PM7, containing a chlorinated-thienyl benzodithiophene (BDT-2Cl) donor unit and a benzodithiophene-4,8-dione acceptor unit. Compared to the control polymer PBDB-T without chlorine substitution, PM7 shows lower HOMO energy level, higher absorption coefficient, enhanced crystallinity and higher carrier mobility. Moreover, the toluene-processed PSCs based on PM7 as donor and small molecule n-OS IT-4F as acceptor achieved a high power conversion efficiency (PCE) of 13.1% with high open-circuit voltage (Voc) of 0.88 V, short-circuit current density (Jsc) of 20.9 mA cm−2 and fill factor (FF) of 71.1%, while the PBDB-T:IT-4F-based PSC only exhibited a low PCE of 5.8% with low Voc of 0.67 V, Jsc of 15.0 mA cm−2 and FF of 57.6%. The PCE of 13.1% is among the highest values reported for the PSCs to date. These results indicate that the chlorine substitution is a simple and effective strategy to design high-performance conjugated polymer photovoltaic materials.

To further elevate the power conversion efficiency (PCE) of organic solar cells (OSCs), ternary strategy is one of the most efficient methods via simply incorporating a suitable third component. Here, a nonfullerene small molecule acceptor MOITIC was incorporated into the state-of-art PM6:Y6 binary system to further enhance the photovoltaic performance. Detailed investigation revealed that MOITIC exhibited a good miscibility and compatibility with Y6, forming alloy-like acceptors in the ternary blends. The alloy-like phase promoted the phase separation and optimized the morphology of ternary blend, which afforded higher and more balanced carrier mobility and reduced charge recombination in devices. Moreover, the larger energy offset between PM6 and MOITIC:Y6 acceptor alloy is beneficial to enhance open-circuit voltage (Voc) of corresponding devices. As a consequence, the optimized ternary OSC (PM6:Y6:MOITIC = 1:1:0.1) showed a significantly increased PCE of 17.1% with simultaneously enhanced Voc of 0.882 V, short-circuit current density (Jsc) of 25.6 mA cm−2, and fill factor (FF) of 75.7%, which has about 9% enhancement compared to the control binary PM6:Y6 (15.7%). In addition, the optimized ternary device exhibited better stability. This work indicates that ternary strategy via combining two compatible small molecule acceptors is effective to simultaneously improve the efficiency and stability of OSCs.

A series of bisindolylmaleimide dyes (IMs) with different N-substituents (IM-PFB, IM-TBA and IM-MB) and planarity (IMC-MB and IM-MB) were designed and synthesized to detect anions selectively and sensitively. The anion-sensing properties were investigated systematically by changing the N-substituents of maleimide, solvent type and molecular planarity. Results indicate that the anion recognition is significantly affected by the solvent type rather than the N-substituents. Different anion sensitivity in various solvents makes IMs selectively detect F− in ACN, H2PO4− in DCM and CN− in THF. Due to the fixed location of two NH groups, the dye IMC-MB with planar structure exhibits poor sensing selectivity in various solvents. The titration curves of anions show that the sensing mechanism of IMs in various solvents for anions is different. The further experimental and DFT/TDDFT calculation results demonstrate that the hydrogen bond interaction and deprotonation of one H atom take place in DCM and THF, respectively, and that the two interactions synchronously exist in ACN. Interestingly, the solvent-dependent anion recognition can make IM-PFB mimic the function of three kinds of decoders (1-to-2, 2-to-3 and 2-to-4), a 4-to-2 encoder and a 1 : 2 demultiplexer. It is really rare for one molecule to mimic so many logic operations.

Author(s): Fan, Q; Su, W; Zhang, M; Wu, J; Jiang, Y; Guo, X; Liu, F; Russell, TP; Zhang, M; Li, Y | Abstract: Herein, three small molecule (SM)-acceptors (POIT-IC, POIT-IC2F, and POIT-IC4F) are developed by combining the side-chain engineering located on the sp3-hybridized carbon atoms of the fused-ring core and the fluorination of end groups. From ITIC to POIT-IC, POIT-IC2F, and then to POIT-IC4F, the SM-acceptors show gradually broadened absorption spectra, increased maximum extinction coefficient, crystallinity, and electron mobilities due to the synergistic effects of side-chain engineering and fluorination. Compared with nonfluorinated ITIC and POIT-IC, as fluorination broadens the molecular spectra, POIT-IC2F and POIT-IC4F with alkoxyphenyl side chains show less decreased LUMO levels than IT-IC2F and IT-IC4F with alkylphenyl side chains, which are conducive to both higher Voc and Jsc for organic solar cells (OSCs). Combined with polymer donor PM6, the POIT-IC4F-based OSCs achieve a device efficiency of up to 13.8% with a high Voc of 0.91 V and Jsc of 20.9 mA cm−2, which are significantly higher than that of the control OSCs based on ITIC (8.9%), POIT-IC (10.1%), or IT-IC4F (12.2%). An efficiency of 13.8% is one of the highest PCEs reported for the annealing-free OSCs. Our results show that the synergistic effects of side-chain engineering and fluorination on SM-acceptor can simultaneously broaden spectral response and minimize voltage loss of OSCs and ultimately achieve high device efficiency.

To achieve efficient polymer solar cells (PSCs), it is important to overcome the energy loss (Eloss) from the optical bandgap to the open-circuit voltage (Voc) of the device by properly matching donor/acceptor (D/A) photovoltaic materials. Here, we develop efficient PSCs based on the absorption complementary pairs of halogenated polymer donors (PM6 and PM7) and an asymmetrical non-fullerene acceptor (IDT6CN-M). The D/A pairs of PM6:IDT6CN-M and PM7:IDT6CN-M show very small highest occupied molecular orbital offsets (ΔEHOMO) of 0.10 and 0.08 eV due to the fact that the halogenation decreases the HOMO levels of polymers, which helps the PSCs achieve a high Voc of 1.04 and 1.05 V, and a small Eloss of 0.56 and 0.55 eV, respectively. Our studies show that the D/A pairs have good morphology compatibility, and the related devices have efficient photon capture and exciton dissociation, balanced and efficient charge transfer and extraction processes. As a result, the PSCs based on PM6:IDT6CN-M and PM7:IDT6VN-M achieved the same high device efficiency of 13.3%, which is one of the highest values for single-junction PSCs with a Voc of over 1.0 V.

Regulating molecular ordering and nanoscale morphology of photoactive layer is crucial to achieve high carrier mobility for fabricating thick-film organic solar cells (OSCs). Herein, molecular ordering and phase separation were finely controlled by varying the substrate temperature in blade-coated PM6:IT-4F devices. The blade-coated devices with low substrate temperature (30 °C) show low crystallinity of IT-4F and poor device performance. However, a high power conversion efficiency (PCE) of 13.64% was achieved for the device blade-coated at 50 °C in air without any other processing treatments, due to the well-ordered molecular packing along the backbone direction of IT-4F molecules. When the film thickness increased to 400 nm, an excellent PCE of 10.22% was achieved in the device blade-coated at 70 °C, which is higher than that of the optimal device blade-coated at 50 °C. This was attributed to the much improved crystallinity within the long-range ordered side-chain packing of IT-4F molecules and the newly emerged small-scale phase separation providing purer domains and continuous charge transport channels. Furthermore, large-Area (90 mm2) devices exhibit high PCEs of 11.39% and 9.76% with a 56 mm2 aperture at film thicknesses of 135 nm and 306 nm, respectively. In addition, the device blade-coated at 70 °C exhibits good storage stability. This work provides comprehensive guidance for optimizing the molecular ordering and nanoscale morphology to fabricate high-efficiency thick-film OSCs.

In addition to high power conversion efficiency (PCE) and good stability, the low-cost of photovoltaic materials is also very important for the practical application of organic solar cells (OSCs). Herein, we synthesized a carboxylate substituted pyrazine-based electron-deficient building block (DTCPz) with a simple structure and low synthetic cost, and then developed a novel wide bandgap polymer donor PFBCPZ. Due to the synergistic electron-withdrawing effects of the fluorination in donor unit (BDT-TF) and esterification and C=N double-bond in DTCPz unit, PFBCPZ shows a deeper HOMO level of −5.60 eV, a strong intermolecular π-π interaction, good crystallinity and stacking, and high hole-mobility of 2.11 × 10−3 cm2 V−1 s−1. Matched with a low bandgap acceptor IT-4F, excellent charge transfer, weak recombination, and small non-radiative energy loss in OSCs was achieved, resulting in an impressive fill factor of 0.785 and a high open-circuit voltage of 0.92 V. As a result, a PCE of up to 15.3% is obtained in OSCs, which is the highest value in the IT-4F-based binary OSCs so far and indicates that low-cost DTCPz with a simple structure is a promising building block to construct high-performance polymer donors for application in efficient OSCs.

Carotenoids have many biological properties and their release from the matrix is most essential for human absorption. Particle size reduction of the matrix can lead to cell wall rupture, which promotes the release of carotenoids. However, changes of rheological property caused by particle size reduction are an important factor affecting 3D printing characteristics. The purpose of this study was to investigate the effect of particle size distribution on the carotenoids release, physicochemical properties and 3D printing characteristics of carrot pulp. The results showed that with the decrease of particle size, contents and release rates of carotenoids showed a trend of increase. Particle size reduction of carrot pulp increased apparent viscosity, G′, G’’, tan δ, 3D printing stability, cohesiveness and gumminess. Moreover, carrot pulp with smaller particle size showed higher printing performance, more uniform pore size distribution and more order microstructures. The study demonstrated that carotenoids release, physicochemical qualities and printing characteristics changed with different particle size distribution, and samples could be separated according to hierarchical clustering analysis of the index.

Molecular ordering and miscibility of donor and acceptor materials play critical roles in developing high-performance as-cast polymer solar cells (PSCs). In this work, a highly crystalline nonfullerene small molecular acceptor, namely, C8-IT-4F, based on alkylated indacenodithieno[3,2-b]thiophene as the aromatic core and 2-(5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile moieties as end groups, is selected and synthesized. The π–π stacking distance in C8-IT-4F film can be tuned from 3.88 Å to a more compact (3.48 Å) state by a film-formation process and the confinement induced by the preaggregated polymer donor PM7, leading to broadened absorption and fine phase separation in the blend film. The optimal morphology with a framework of preaggregated polymer donor, J-type face-on π–π stacked acceptor, and appropriate donor/acceptor miscibility facilitates charge generation and transport and reduces charge recombination. As a result, the best PSC based on the as-cast PM7:C8-IT-4F blend film exhibits power conversion efficiency of 14.3%, with an open-circuit voltage of 0.82 V, a short-circuit current density of 22.7 mA cm−2, a fill factor of 77.1%, and good photostability with a stabilized fill factor.

A novel wide-bandgap conjugated polymer (PTZP) based on alkylphenyl-substituted benzo[1,2-b:4,5-b′]dithiophene (BDT-P) as the electron-rich unit and thiazolo[5,4-d]thiazole (TTz) as the electron-deficient unit was designed and synthesized for the non-fullerene polymer solar cell (PSCs) application. The polymer exhibited a wide bandgap of 2.01 eV with a strong absorption in the range of 300-620 nm, which was complementary with that of the fused-ring small molecule acceptor (SMA; 2,2′-((2Z,2′Z)-((4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl)bis(methanylylidene))bis(3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile, IDIC). Also, the polymer exhibits a deep highest occupied molecular orbital (HOMO) energy level of -5.41 eV. Furthermore, the polymer film possesses strong crystallinity and dominated face-on stacking with a small d-spacing of 3.65 Å, resulting in a high hole mobility of 4.01 × 10-3 cm2 V-1 s-1. The optimal PSCs based on the PTZP:IDIC blend showed a high PCE of 11.8% with an open-circuit voltage (Voc) of 0.90 V, a short-circuit current density (Jsc) of 17.9 mA cm-2 and a fill factor (FF) of 73.3%. Moreover, the device with an active layer thickness of up to 200 nm or area of up to 0.81 cm2 exhibited outstanding performance, with PCE of over 10%, resulting from the excellent molecular stacking. These results revealed that PTZP will be a promising conjugated polymer for the fabrication of efficient large-area PSCs.

Agricultural commodities markets provide an important venue for the transfer and pricing of large volumes of key inputs of food production. The structure of the market and the activity and motivations of market participants are factors in pricing stability and ultimately the costs for food produced and consumed on world markets. This paper uses a modified behavioural finance model and trader categories defined by the Commodity Futures Trading Commission to examine sentiment-driven price changes and speculative activity in wheat, soybean, rough rice, soybean meal, soybean oil, corn and live cattle. The paper further combines a Vector Autoregression (VAR) model and Cumby-Modest tests to describe the positive feedback trading behaviour of different investors. The analysis shows that speculators are positive feedback traders and that, while previous returns influence sentiment, sentiment does not influence returns except when sentiment is high.

Generally, highly efficient organic solar cells require both a high open-circuit voltage (V OC ) and a high short-circuit current density (J SC ). Reducing the energy loss (E loss ) is an effective way to achieve a high V OC without compromising the photocurrent, which is ideal for enhancing the power conversion efficiencies (PCEs). Herein, a new chlorinated nonfullerene acceptor (ITC-2Cl) with chlorinated thiophene-fused end groups is developed. In comparison with the unchlorinated counterpart (ITCPTC), the introduction of Cl improves not only the electronic properties by redshifting the absorption spectra and deepening the lowest unoccupied molecular orbital energy levels, but also the molecular packing and thus thin-film morphology. The PM6:ITC-2Cl-based device yields a significantly higher PCE (13.6%) with a lower E loss (0.67 eV) than the ITCPTC-based device (PCE of 12.3% with E loss of 0.70 eV). More importantly, compared to the archetypal nonfullerene acceptors such as IT-4F (PCE of 12.9% with E loss of 0.73 eV) and IT-4Cl (PCE of 12.7% with E loss of 0.76 eV), the ITC-2Cl-based device shows a higher PCE and a lower E loss . These results demonstrate that the chlorinated thiophene-fused end group is a promising candidate for a high-performance nonfullerene acceptors with low energy loss.

Poly- and single crystalline NbSi 2 specimens with different microstructures were prepared by arc-melting, spark plasma sintering (SPS) and optical-heating floating zone melting for oxidation experiments at 1023 K. The effects of cracks, pores and grain boundary in the microstructure on the oxidation behavior of NbSi 2 were investigated. For arc-melted poly-crystalline specimens containing micro-cracks, NbSi 2 fully turned into powders after 3 h exposure at 1023 K, which is known as the “pesting” phenomenon. As a comparison, no pesting was found in the dense SPS poly-crystalline specimens and single crystals after 89 h. The oxide scale consists of Nb 2 O 5 and SiO 2 . The oxidation kinetics of all specimens follows a linear law. The oxidation rate was higher in the poly-crystalline specimen in comparison to single crystalline. The mechanism of oxidation has been analysed using a kinetic model.

Oxidation processes of poly and single crystalline NbSi2 were observed in situ by high temperature optical microscopy to clarify the pest phenomenon. Pest disintegration is mainly determined by the pre-existing cracks in the microstructure. Porosity and grain boundary are the preferential oxidation sites. Pest oxidation of NbSi2 at 1023 K is not an intrinsic material property.

The effect of grain boundary character distribution (GBCD) on the secondary working embrittlement (SWE) of interstitial-free (IF) steels has been evaluated. It is shown that cracks propagation along the high-energy continuous “random” boundaries results in the SWE and low-energy boundaries offer obstacles to the propagation.